Development of spectroscopic system for the measurements of stratospheric OClO and BrO

点击翻译按钮获取中文摘要

An automated grating spectrometer has been developed for possible measurements of OClO and BrO in the stratosphere by zenith sky technique. The monochromator has a field of view of F4.2 using a 68x68 mm, 2400 grove/mm grating. The detector is a 9804 photomultiplier and its gain is adjusted over a range of 2x105 by varying the high voltage. Wavelength is scanned by rotating the grating using a sine bar mechanism driven by a stepping moror. The wavelength region covered is 430-502 nm for the current tests. Processing uses 432 to 500 nm of this spectrum. The cross sections fitted are NO_2, O_3, H_2O, Ring effect, Rayleigh scattering and O_4, NO_2 and O_3 column amounts have been determined with 1 % precision. Residual absorption after subtraction from the observed total absorption is less than 0.1 %. This fulfillls necessary condition for the detection of OClO and BrO.